Method of and apparatus for cutting staple lengths of cables of artificial threads



March 14, 1961 MAX-OTTO SCHURMANN ETAL 2,974,554

METHOD OF AND APPARATUS FOR CUTTING STAPLE LENGTH-S OF CABLES OF ARTIFICIAL THREADS Filed Jan. 5, 1955 FIG. 4

INVENTORS: MAX OTTO SCHURMANN, ALFRED EINSEL the same direction.

United States METHOD or AND APPARATUS FOR ,CUTTING suAPI gENGTHs F CABLES 0F ARTIFICIAL Max-Otto Scliiirmann and Alfred Eins el, Dormagen, Germany, assignors to Farbenfabriken Bayer Aktiengesell- 'schaft, Leverkusen, Germany, a corporation of German Filed Jan. 3, 1955, Ser. No. 479,373

Claims priority, application Germany Jan. 2, 1954 5 Claims. (CI. 83-22) I This invention relates to a method' of and apparatus for cutting staple lengths of cables of artificial threads. In a known method of obtaining a constant staple length, a wet cable of thread is supplied to a cutting when the threads are still soft from manufacture and are more or less ta'ck'y, as is the case, for example, when cutting cables of staple fibres in a semi-coagulated con- ;dition. The pressure of the supply rollers then causes ,thecapillary threads to deform or stick, thereby making it diflicult or impossible for the bundles of fibres to be subsequently loosened. Moreover, experience has shown that with apparatus for carrying out this known method breakdowns in operation and the formation of waste is to be expected to a not inconsiderable degree due to the thread cable being wound onto the pairs of feed rollers, the travelling cutting support or on the guide rollers of the support.

It has now been found that these disadvantages are eliminated if, in accordance with the invention, the thread cables are supplied in the wettest possible condition and depend substantially vertically to a cutting device having knives which operate with a pressure action against a support (preferably an elastic support) moving in the same direction.

A movement which is in practice completely free from interruptions is obtained by working in this .manner. Not only are the coalescing effects avoided, but, due to the weight of the liquid adhering thereto, the cable travels towards the cutting device so smoothly and so uniformly that it' is possible to obtain an absolutely uniform staple length. The more liquid that adheres to the cable, the more smoothly it runs. This effect may be further assisted by providing the cable with a supplementary sheath of liquid during its travel from the supply member to the cutting device, for example, by means of a funnel which is provided with a liquid supply in its upper part. The cross-sectional form of the funnel opening is expediently adapted to the cross-section of the cable: this is desirable in order that the excess of liquid does not become too great locally and interfere with the steady running of the apparatus. The supplyof addi-' were tional liquid also facilitates the detachment of the cuttings from a counter-acting roller. It is also important for steady running, and thus for uniformity of the staple length, that the speed or rotation of the knife roller should at least substantially correspond to the speed of the thread cable, so that a lifting or buckling is avoided, since otherwise (particularly in the former case) the depending cable is set vibrating transversely. Small variations of the set staple length may, however, be ob- 2,974,554 Patented Mar. 14,19 61 2 tained by simply varying the knife speed (with constant delivery speed) or by varying the supply speed (with constant knife speed). 0n the other hand, it relatively large staple variations are necessary, it is expedient to operate in such manner that either the diameter of the knife shaft or the number of knives is modified. The feed may be'eifected by simple rollers or groupsv of rollers which do not contact one another. It is important for maintaining the constant cut length that, slipping of the wet cable is avoided, particularlywhen only a single roller is used for the direct supply. This is best eifect ed by supplying the cable to the roller only at a tension which corresponds substantially to the weight of the freely depending end of the cable. In practice, it is possible to proceed in such manner that the tension of the cable comingvv from the spinning machine is taken up by a group of, for example, three or five driven rollers which are not in mutual contact, and that the cable travels with only slight tension, i.e. freely depending in a loop, to the actual feed roller or roller group. The sag of this loop may be controlled automatically, for example, by means of mechanical or optical impulses. It has, however, been shown that without automatic control it is also easily possible to obtain a satisfactoryconstancy of the sagby using only manual control.

An apparatus for carrying the method into effect according to the invention comprises a supply roller or a group of rollers which are not in mutual contact, and a cutting device whichvis disposed vertically thereon and has a driven knife roller adapted to press against a support moving in the same direction. A roller or. an

'roller or a roller with a rubber covering fixed on it, the

rubber sheath has the advantage that it may readily be interchanged.

It has further been found that it is possible for both the construction and operation of the apparatus to be considerably simplified if a driven knife roller counteracts with a roller which rotates freely with it. This also substantially contributes to the desired steady running and, in addition, causes a considerably smaller amount of wear on the rubber sheaths and cutting knives, since it is not possible for any relative movement to occur between the cutting edge of the knife and the rubber surface.

In the accompanying drawings:

. Figures 1 to 3 are diagrams illustrating various arrangements according to the invention, and

Figure 4 is a cross-sectional diagram illustrating a funnel forming part of the arrangement illustrated in Figure 3.

Figure 1 shows a feed device consisting of rollers 11, 12, 13, 14, 15 and 3a which are not in mutual contact: the feed device as described below allows a cable 4 to travel in a freely depending form to a cutter device which consists of a driven knife roller 5 and a freely rotatable counteracting roller 6 which is covered with a soft rubber sheath.

Figure 2 shows a similar arrangement having rollers 1 and 3, but one which is provided with a rubber belt 9 travelling around two rollers 7 and 8 and serving as an elastic support. This arrangement has the advantage that it is possible for the staple lengths to be easily removed by a stream of liquid 10 flowing past the lower roller 8.

In the arrangement illustrated in Figure 1, the last feed roller 3a is constructed as a webbed roller, i.e., a roller provided with arms or side bars as shown in the drawing, which reduces the adhesion between the cable 4 and the roller. The other conveyor elements may, of

course, also be constructed as webbed rollers.

Figure 1 illustrates an arrangement in which the tension of the band from the spinning machine is taken up bya'group of five rollers 11, 12', 13 1'4 and 15"- travelling with a slight lead as is indicated by the sag in the band between rollers 15 and 3a, the cable 4 then travelling with a smaller tension to the feed roller 3a. proper by depending in a loop.

Figure 2 illustrates similarly this feature of a loop between guide and support roller 1 and feed roller 3.

Figures 3 and 4 show the supply of a supplementary liquid sheath through a funnel 16 having a flat thread cable passing through it.

We claim:

1. In the method of cutting staple lengths of' artificial tows, in which the moving tow is out against a. support surface moved in the same direction therewith, the improvement which comprises passing the tow in substan- 'tially completely wet condition along a freely depending loop path between a guiding and supporting surface and a feeding surface, thence passing the tow over said feeding surface and downwardly therefrom in a substantially vertical direction in freely suspended condition to the point of cutting with said tow engaging said guiding and feeding surfaces under pressure due solely to the weight of said tow.

2. Improvement according to claim 1, which includes coating the tow being passed to the point of cutting with a supplementary liquid sheath.

3. Apparatus for cutting staple lengths of artificial tows which comprises cutting means including a knife roller having at least one cutter blade radially extending therefrom and a movable resilient support surface, said cutter blade being movable in the same direction as said support surface in cutting engagement therewith upon rotation of said knife roller, said cutting means being positioned for receiving and cutting a substantially vertically, downwardly moving tow, and means positioned substantially vertically above said cutting means including a guide and support means and a feed means laterally spaced from said guide, and support means for passing a substantially completely wet tow therebetween in a freely depending loop and for feeding the tow over the feed means. and downwardly therefrom to the cutting means in freely suspended condition, with said tow engaging said guide and feed means under pressure due solely to the weight of the tow.

4. Apparatus according to claim 3 in which said guide and support means includes at least one guide and support roller and said feed means includes at least one feed roller.

5. Apparatus according to claim 3, including means for coating a tow being passed downwardly to said cutting means with a liquid sheath.

References Cited in the file of this patent UNITED STATES PATENTS UNITEFSTATES PATENT OFFICE CERTIFICATION CORRECTION Patent No. 2 974 554; March 14L 1961 Max-0tto Schiirm'ann et al It is hereby certified that error appears in the above numbered pate'nt requiring correction and that the said Letters Patent should read as corrected below.

Column 2-, line 58, before, "cable d lu e a column 4,- line 20 after "a liquid sheathr" insert the following claim:

6. Apparatus according to claim 3, in whichsaid support surface is a resilient support surface defined on an endless b'elt rotatable in the same periphegral direction as said knife roller and positioned for cutting engagement with said blade upon rotation of said knife roller.

in the heading to the printed Specification, line 11, for "5 Claims" read 6 Claims v Signed and sealed this 3rd day of October 1961.

(SEAL). Attest:

ERNEST W. SWIDER DAVID A Attesting i Commissioner of Patents 

